Orthogonal beam forming network
First Claim
1. A method of expanding an orthogonal beam forming matrix, having a first plurality of antenna elements ports, into a matrix having a second plurality of ports, said second plurality of ports being coupled to a respective number of antenna elements greater in number than said first plurality of ports, comprising the steps of:
- isophase coupling said first plurality of ports to a like number of respectively positioned ports of said second plurality of ports;
coupling at least one port of said first plurality of ports to a corresponding numbered additional port of said second plurality of ports adjacent the isophase coupled ports; and
effecting an additional 180°
phase shift of signals coupled between said at least one port and said additional port.
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Accused Products
Abstract
A binary Butler matrix is expanded into a non-binary matrix coupled to a like number of non-binary antenna elements for forming multiple beams from a phased array and wherein an n×n Butler matrix drives n+l elements, and where the l elements are coupled to predetermined ports of the Butler matrix normally coupled to the n elements but coupled thereto through respective 180° phase shifters such that, for example, the first or (n+1)th element to the right of the nth element is coupled to the same port of the Butler matrix coupled to the 1st element but additionally through a fixed 180° phase shifter while the first or 0th element to the left of the 1st element is coupled to the nth same port coupled to the nth element but including a respective 180° phase shifter. Progressively increasing numbers of elements on either side of the n elements are respectively coupled to ascending and descending numbered ports of the binary matrix through respective 180° phase shifters, the result being an amplitude taper of the composite beams formed thereby.
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Citations
20 Claims
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1. A method of expanding an orthogonal beam forming matrix, having a first plurality of antenna elements ports, into a matrix having a second plurality of ports, said second plurality of ports being coupled to a respective number of antenna elements greater in number than said first plurality of ports, comprising the steps of:
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isophase coupling said first plurality of ports to a like number of respectively positioned ports of said second plurality of ports; coupling at least one port of said first plurality of ports to a corresponding numbered additional port of said second plurality of ports adjacent the isophase coupled ports; and effecting an additional 180°
phase shift of signals coupled between said at least one port and said additional port. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of expanding an orthogonal beam forming matrix comprising a binary (n=2m) Butler matrix having n input ports and n output ports into a non-binary matrix having n+l output ports coupled to a respective number of n+l antenna elements and where l≦
- n, comprising the steps of;
isophase coupling the n output ports of the Butler matrix to n ports of the n+l output ports; coupling the 1st output port of said n output ports to the (n+1)th port of said n+l output ports to the right of the nth port thereof and effecting an additional 180°
phase shift of signals therebetween. - View Dependent Claims (10)
- n, comprising the steps of;
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11. Apparatus for expanding an orthogonal beam forming matrix, having first plurality of output ports normally coupled to antenna elements, into a matrix having a second plurality of output ports coupled to a respective number of antenna elements greater in number than said first plurality of output ports, comprising:
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means isophase coupling said first plurality of output ports to a like number of respectively positioned ports of said second plurality of ports; means coupling at least one port of said first plurality of ports to a like numbered additional output port of said second plurality of output ports adjacent said isophase coupled ports; and means providing an additional 180°
phase shift of signals coupled between said at least one output port of said first plurality of ports and said additional output port of said second plurality of ports. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. An orthogonal beam forming network for a phased array antenna including n+l antenna elements comprising:
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a binary n×
n matrix having n input ports and n output ports, said n output ports being isophase coupled to n elements of said n+l antenna elements and where l≦
n;means additionally coupling the 1st output port of said n output ports of said binary matrix to the (n+1)th antenna element to the right of the nth antenna element and including means providing an additional 180°
phase shift of signals therebetween; andmeans additionally coupling the nth output port of said n output ports of said binary matrix to the 0th antenna element to the left of the 1st antenna element and including means providing an additional 180°
phase shift of signals therebetween, whereby said binary matrix is transformed into a non-binary matrix. - View Dependent Claims (20)
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Specification